Dresden 2026 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

MA: Fachverband Magnetismus

MA 2: Altermagnets I

MA 2.9: Talk

Monday, March 9, 2026, 11:45–12:00, HSZ/0004

X-ray magnetic circular dichroism of altermagnet α-Fe2O3 based on multiplet ligand-field theory using Wannier orbitals — Ruiwen Xie, Hamza Zerdoumi, and •Hongbin Zhang — TU Darmstadt, Darmstadt, Germany

Hematite α-Fe2O3 is a g-wave altermagnet, possessing an easy-axis and easy-plane weak ferromagnetic phase below and above Morin temperature, respectively. The presence of these phases renders it a good candidate to study the characteristic spin splitting in altermagnets under the impacts of relativistic effect and finite temperature. We have calculated the band structure of α-Fe2O3 based on density functional theory (DFT) considering the Coulomb correction and spin-orbit coupling effects. Additionally, the DFT + dynamical mean-field theory calculations have been performed at finite temperatures. It is found that the spin splitting in α-Fe2O3 preserves with either SOC or temperature effect included. Furthermore, we present a numerical simulation of the x-ray magnetic circular dichroism (XMCD) of the L2,3 edge of Fe using a combination of DFT with multiplet ligand-field theory. In terms of the different Néel vectors present in α-Fe2O3, we calculate the x-ray absorption spectroscopy of the L2,3 edge of Fe in the form of conductivity tensor and analyze the XMCD response from a perspective of symmetry. A characteristic XMCD line shape is expected when the Néel vector is along [010] direction and the light propagation vector is perpendicular to the Néel vector, which can be further distinguished from the XMCD response originated from weak ferromagnetism with the light propagation vector parallel to the Néel vector.

Keywords: Altermagnet; Spin splitting; XMCD; Multiplet ligand-field theory